Water distribution system for swimming pools



Jan. 16, 1968 H. s. ELLIS 3,363,767

WATER DISTRIBUTION SYSTEM FOR SWIMMIG POOLS Filed May 20, 1965 3Sheets-Sheet l Jan. 16, 1968 H. s. ELLIS 3,363,767

WATER DISTRIBUTION SYSTEM FOR SWIMMING FOOLS Filed May 2o, 1965 5Sheets-Sheet 2 Jan. 16, 1968 l H. s. ELLIS 3,363,767

WATER DISTRIBUTION SYSTEM FOR SWIMMING POSLS Filed May 20, 1965 5Sheets-Sheet 3 a 3a 7/ 7i 70 x (30 7/ 7a 60 706 65 J7 M 75 4 l 4 u 67 57a 54, 5 u l Y f 7 @a A/// @4 i 'mmm mumml. g 'Hummm 5 55 .5

y qu 5 59 u United States Patent O 3,363,767 WATER DISTRIBUTION SYSTEMFOR SWIMMING POOLS Herbert S. Ellis, Albany, NX., assignor to LifetimeMetal Products, Inc., Columbus, Ohio, a corporation of Ohio Filed May20, 1965, Ser. No. 462,165 Claims. (Cl. 210-169) ABSTRACT OF THEDISCLOSURE A water distribution system for swimming pools wherein theswimming pool has a gutter whose inside Wall forms an incomingwater-carrying conduit `and at least one yWeir in the upper portion ofthe conduit permitting water to ilow from the pool into the gutter, thedisclosure further including a surge tank and iilter system having aselectively positionable valve which is Operable to maintain a properlevel of water in the swimming pool.

This invention relates to a water distribution system for swimming poolsand more particularly the invention is an improvement in the conduitsystem shown in the Ogden Patent 2,932,397.

Prior to the Ogden invention, it had been the practice in installingswimming pools to bury in the terrain in the area surrounding theswimming pool a main pipe for carrying water into the swimming pool.From that main pipe, distribution pipes were connected into the swimmingpool wall below the water level to convey water into the pool at anumber of points spaced around the pool periphery. Although this systemhad been used for many years, and is still `being used today, it had anumber of serious disadvantages. Depending upon the corrosive quality ofthe soil in which the pipes were buried, the pipes might `deteriorate tothe point of unusability in as short a time as three years. The repairof the pipes required the excavating of the terrain surrounding the poolto provide access to the pipes to permit their repair or replacement.Additionally, the Iburied pipes did not admit of continuous inspectionwhich would enable the early detection and economic replacement ofdeteriorating sections.

The Ogden invention has proved to be `a remarkable improvement over theexisting distribution systems dscribed above. In accordance with theOgden invention, the `distribution conduit for carrying water around theperiphery of the pool is mounted in an` exposed position on the poolwall and provision is made for jet nozzles spaced along the length o'fthe conduit 'for the emission of water directly into the pool.Preferably, the conduit forms the inner wall of the periphery poolgutter so as to facilitate its fabrication and installation. Obviously,the Ogden structure eliminates the disadvantages attending the `buryingof pipe in the terrain surrounding the swimming pool and lfurthereliminates the need for connections from `that buried pipe into the wallof the pool. Since all conduit except the main drain Vfrom the bottom ofthe pool is exposed, it is easily accessible for regular maintenance andrepair.

It has been an objective of the present invention to provideimprovements in the Ogden structure 'for the complete and eifectiverecirculation of water. The iirst of these is constituted yby at leastone and preferably a plurality of integral skimming weirs which aremounted in the peripheral conduit. More specifically, a small portion ofthe top wall of the pool conduit is removed to provide `a notch in theconduit and the weir structure is mounted in that notch, thereby sealingthe top wall on the conduit. The Weir provides a transverse passagethrough the top portion of the conduit to permit water to flow from thepool to the gutter. A gate is pivotally mounted in the weir for movement.between a position in which the transverse passage is blocked and aposition in which it is out of lthe Way of `the passage. Means areprovided for selectively locking the gate in one of its two position. AWeir is preferably mounted in each corner of the pool.

The integral skimming weir structure of the invention permits the properflow of water into the gutter during the two main conditions ofoperation namely the active condition in which the pool is lled withswimmers and the quiescent condition which contains when the poo-l isclosed. 'During the active condition, the Weir gates are closed, therebypreventing the flooding of the gutters. Water is splashed into thegutters through the iactivity of the swimmers, and, additionally, theminimum amount of water required vfor the purposes of gutter sanitationand gutter ilow direction is supplied -by jets connecting the conduit tothe gutters.

During the quiescent periods, the gates are swung open and maintained inan open positions by the locking means. During this period, the poollevel may be maintained at any level between the upper and lower edgesof the Weir opening to permit the surface water of the pool to Owthrough the weirs. By locating the weirs at each corner of lthe pool,effective skimming action of the surface Wall and `debris lying on thesurface is attained regardless of the direction of any surface winds.

Another feature of the invention which is collateral t0 the .provisionof the integral skimming weirs described above resides in theaccessibility of the interior of the conduit permitted by the removableweir structure. This accessibility is important in several respects, themost important of which being the ability to introduce sacri'licalanodes into the conduit interior and to maintain a regular inspection ofthe anodes. Through this feature of the invention, coupled with regularinspection and maintenance on the part of pool personnel, the life ofthe conduit system can be indefinitely prolonged.

Another objective of `the invention has been to provide a pool having anintegral skimming Weir at each corner of the pool, the weirs beingoriented relative to each other to permit the introduction ofsaeriiicial anodes so oriented that they extend substantially over theentire length of the conduit.

It has been another objective of the invention to provide an improveddistribution system, including a pump and iilter system, co-operatingwith the conduit return gutter and main drain which permits lthe properhandling and iiltration of the pool -water under varying conditions ofilow without requiring a iloa-t valve, which is subject to sticking andmechanical failure.

Another objective ofthe invention has been to provide a pool cornerstructure incorporating the integral skimming weir described above whichadmits of prefabrication and ease of installation at the poolside.

Another objective of the invention has been to provide a waterdistribution system `for a swimming pool comprising, a surge tank havingfilters therein, means forming an open gutter around the periphery ofsaid pool and connected to said surge tank, a pipe extending around theperiphery of said pool and forming the inner wall of said gutter, aplurality of outlet nozzles in said pipe directing water downwardly intosaid pool, at least one transverse passageway through the upper portionof said pipe, means for selectively opening or closing said passageway,a main drain and conduit connecting the bottom of said pool to saidsurge tank, a selectively positionable valve in said conduit, and a pumpand conduit means connected between said surge tank and pipe to `drawwater through said `filters and into said pipe.

These and other objectives of the invention will become more readilyapparent from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a diagrammatic top plan view partly in section of a swimmingpool employing the present invention,

FIG. 2 is a cross-sectional view of the gutter section taken along lines2 2 of FIG. l,

IFIG. 3 is a fragmentary perspective View partly in section showing theWeir section,

IFIGS. 4 and 5 are cross-sectional Views taken along lines 4-4 of FIG.3, and

FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 5.

Referring to PIG. l of the drawings, a swimming pool `161 has an opengutter 11 around its periphery, the gutter having an inner wall 12formed by a hollow pipe 13. The gutter 11 and pipe 13 are connected to afilter system 14. The filter system 14 includes a surge tank 115 inwhich one or more 4filter units 16 are located. The gutter 11 isconnected directly to the surge tank 15 so that the water in the gutterilows under the force of gravity into the surge tank. The lter units 16are connected by a manifold 17 to a conduit 1S which projects through awall 19 o'f the surge tank. A pump 20 and conduit 21 connect the conduit18 tothe pipe 13.

The pool has a main drain 24 connected by a conduit 25 to the surge tank1S. The conduit 25 has a selectively positionable valve 26 with whichthe ilow rate of water from the drain 24 into the surge tank 15 can bevaried. The filter system has other plumbing which is used for cleaningthe filters, draining the pool and the like, but the additional plumbingis conventional and does not form a part of the present invention.

The `filter system illustrated in a vacuum system in which the water inthe surge tank is drawn through the filters by means of the pump 2t)whose low pressure side is connected to the lfilter. The distributionsystem of the present invention is substantially equally usable withother well known filter systems, these including the severalcombinations of an open or a closed balancing tank and a pressurediatomite filter or a pressure sand filter. The open balancing tank iscomparable to the surge tank 15 and is installed with its upper levelslightly above the level of the pool. `Either a pressure diatomite orpressure sand filter is made as a separate unit and connected to it by apump and conduit, the low pressure side of the pump being connected tothe tank and the high pressure side being connected tothe lfilter. Theclosed balancing tank is similarly connected to either type of pressurelfilter but is located below the level of the pool. The selectivelypositionable Valve 25 may be used in these systems to connect the maindrain of the pool to the tank and to maintain a minimum water level inthe tank. With the open and closed ba-lancing tanks, however, it ispreferable to use a -float valve in the tank to regulate the maximumlevel of water in the tank by controlling the flow through the maindrain.

It can be seen that the surge tank is supplied with water from the maindrain and from the open gutter 11. Filtered water is returned -to thepool only through the pipe 13 and the conduit 21, which connects thepipe 13 to the pump 20. Around the periphery of the pool, as for exampleon three foot centers, are a plurality of nozzles 28 (see FIG. 2) bywhich the water is directed from the pipe 13 into the pool. The nozzleslare downwardly directed, preferably at an angle of approximately to thevertical side wall 29 of the pool.

An integral skimming Weir 3@ is located at each corner of the pool. Theweir is formed by a notch in the upper portion of the pipe 13, the notchforming a transverse passage between the pool and the gutter 11. Meansare provided for selectively opening or closing the passage foroperation under the two principal conditions of operation; namely, thecondition of swimming activity with its turbulent water, and thequiescent condition occurring when there are no swimmers in the pool.

Even under the best conditions of maintaining proper pool chemistry, thepool water tends to be corrosive. The outside of the surfaces of thepipe 13 and gutter section are normally painted, thereby preventing thecorrosive attack on the outside surface of the metal. However, on theinside surface of the pipe 13, a sacrificial anode 31 is provided topreserve the pipe. Under normal water conditions the sacrificial anode31 may be disintegrated in a two to live year period and requires oneyearly inspection. The disposition of the weirs 30 at the corners of thepool permits the inspection and replacement of the anodes at regularintervals. Each anode extends substantially the full length of thesection of pipe in which it is located and can be installed by removingthe Weir structure and sliding the anode into the section of the pipe 13through the hole left by the -removal of the Weir structure. It will benoted that each weir .3@ is similarly located with respect to thecorner, that is, as viewed from the center of the pool, each Weirappears at the right of the corner. This positioning permits theintroduction of anodes into each straight section of pipe 13 so thatsubstantially the entire perime- -ter ofthe pool is protected.

One example of a gutter installation is illustrated in FIG. 2 showingthe gutter installed on a granite pool. The concrete which forms thepool wall is indicated at 35 and has anchor rods '36 embedded in it, theanchor rods having threaded ends 37 used to level the gutter sectionduring installation. A unitary gutter section is constituted by a backwall 3S forming the pool curbing, a `bottom wall 39, and the pipe 13forming the front wall of the gut-ter 11. A metal stiffener 4t) iswelded to the back wall 38 and an angle anchor bracket 41 is welded tothe bottom walls and to the pipe 13, the anchor bracket being secured tothe anchor bolts 36 by the nuts 42. A concrete pool deck, shown in partat 43, is filled in behind the back Wall 38 of the gutter section up toa barrier 44, which 'forms an expansion joint between the gutter sectionand the concrete deck.

The back wall 38 of the gutter section has an inclined inner surface 46extending above the upper surface of the pipe 13. The surface 46 has animportant function of directing water which is splashed over the pipe 13as indicated by the arrow 47 down into the gutter 11 as indicated by thearrows 48 and 49. Thus, the water which is splashed over the pipe 13 isalmost entirely directed into Ithe gutter rather than being splashedback into the pool.

This surface water, which is the most highly contaminated of all thepool water, is thus continually taken off the surface of the pool waterand directed to the .filter system.

Not only does the gutter configuration, particularly in,- cluding thesurface 46, assist in the recirculation of the pool water to the filtersystem, but additionally the gutter section provides a fast pool forcompet-itive swimming. By eliminating the slash back of water againstthe pool walls, a much smoother surface of the pool water is maintainedduring competitive swimming.

One method of installing the integral skimming weir is illustrated inFIGS. 3 to 6. The Weir section is mounted in a notch 5@ formed in theupper portion of the pipe 13. In a generally rectangular pipe, which issix or eight inches high and four inches wide, for example, the notch iscut to a depth of approximately two inches. The notch creates a top edge51, side edges 52 and a bottom edge 53 in the pipe. A wall 54 is weldedinside the pipe A13 at each end of the notch to provide a seal along thetop edge S1 and the side edges 52. The wall 54 has a flange SS which,along with the bottom edges 53 of the notch, forms a support for abottom plate 55. A gasket 57 is clamped between the bottom plate 56 andthe support formed by the flange SS and the bottom edges 53 of thenotch. A pair of longitudinally extending blocks S3 are welded to theinside surface of the pipe 13 immediately below the bottom edges 53 andhave a series of spaced internally threaded holes to receive bolts 59 bywhich the bottom plate 56 is secured in the notch. When the bottom plate56 is securely fastened in the notch, clamping the gasket 57 between itand the bottom edge 53 and the iiange 55 a seal is formed preventing anyescape of the water under pressure from the pipe 13.

A top plate `60 is mounted in the notch with its end edges in abuttingengagement with the top edge 51 and side edges 52 of the notch Sil. Thetop plate 60 is secured to the bottom plate S6 by two bolts 61, each ofwhich passes through a collar 62 and is threaded into a theraded hole`63 in the bottom plate S6. The top plate 6! has depending side walls 64(see FIG. 6), the upper portion of the side walls `64 being bored as at65 to receive pivot pins 66 by which a gate 67 is pivoted in the weir.The combined top plate 60 and bottom plate 56 form a transversepassageway 63 through which water skimmed from the surface of the poolmay pass when the gate is swung upwardly to a horizontal position asindicated in FIGS. 5 and 6.

The gate 67 may be held selectively in either the open position orclosed position by a retainer arm '76. The retainer arm is Z-shaped andhas a leg 71 threaded into an internal bore in a set screw 72, which isthreaded into the top plate 6i). The attachment of the retainer arm tothe set screw '72 permits the arm to be pivoted in a horizontal planeuntil it extends longitudinally of the Weir thereby permitting the gate67 to be swung between its two positions. After the gate is properlypositioned the retainer arm is swung back to a transverse position inwhich it holds the gate in a closed position by bearing on the rearsurface of the gate (see FIG. 4). Alternatively, the gate is held inopened position as viewed in FIG. 5 by providing a support on which thegate rests in its upward position.

Within the pipe 13 and immediately below each Weir, a bolt 75 is weldedto the wall of the pipe. The bolt has a nut 76 threaded onto it by whicha pigtail 77 may be electrically connected to the wall of the pipe. Theother end of the pigtail is welded to the sacrificial anode 31; thereby,completing the electrical circuit. The electrical circuit is, of courseconstituted by the anode 31, the pigtail, the pipe 13 and the pool waterin the conduit which constitutes an electrolyte.

A gutter wash nozzle 78 is mounted below the weir on the pipe 13 by abolt 79 threaded into a hole in the wall of the pipe. The wall has twoholes Sti communicating with the nozzle to permit a continuous supply ofwater to the nozzle thereby assuring a continuous washing of the gutter.

Operation in the operation of the pool, the pool is first illed from afresh water line indicated at til in FIGURE r1, the water beingintroduced into the surge tank where it is filtered and pumped into themain distribution pipe 13. During this filling operation, the gates inall weirs are maintained closed so that the level of the water can bebrought up to about an inch from` the top of the pipe 13. After the poolhas been filled to that level, the incoming water is turned ofi. Withthe pump running, the valve 26 in the main drain conduit 2-5 ismanipulated to vary the flow from the main drain to the surge tank untila steady state condition is maintained in which the water level in thesurge tank 15 is about six inches over the filter elements. The level ofthe water in the pool may be approximately two feet higher than thelevel of the water in the surge tank, under these conditions, therebyproviding the head necessary to drive the water through the restrictedopening of the valve 26. If the level of the water in t-he surge tankshould drop any lower, the head of course, increases thereby providinggreater pressure to drive water into the surge tank. Thus, bypreselecting the minimum condition of the level of water in the surgetank through the positioning of the valve 26, an automatic regulation ofthe level of the water in the surge tank can be maintained without theuse of a float valve.

lUnder normal operating conditions, the level in the surge tank will bemaintained about two feet over the top of t-he filter elements. Theadditional water required to maintain that level in the surge tank comesfrom the gutter 11. Under active conditions of pool operation, the weirs30 are maintained in a closed condition and water is driven into thegutters by the activity of the swimmers in the pool splashing water overthe pipe 13. During the active period, it is necessary to close the weirgates in order to prevent the flooding of the gutters, which would causean improper operation of the circulating system.

When there are no swimmers in the pool, the weirs are opened and thewater pours into the gutters from the passageways 63 formed by theweirs. By providing a weir at each of t-he corners of the pool, thedirection of the wind has no effect on the successful skimming action ofthe system. No matter which direction the wind is blowing, it will drivethe debris and surface scum toward at least one of the weirs therebyeifectively cleaning the surface scum from the pool during the quiescentnighttime operation.

By directing the incoming jets 28 downwardly at an angle ofapproximately 45, the filtered water coming into the pool is drivenagainst the bottom of the pool and provides a scrubbing action to raisethe sediment from the bottom of the pool toward the upper surface.Further, by bringing the incoming water down to the bottom of the pool,the more contaminated water at the surface of the pool is splashed intothe gutters by the activity of the swimmers or moves into the guttersthrough the weirs during the quiescent stage of operation. Thus,regardless of the conditions of operation, the system provides for theconstant introduction of clean chlorinated water into the bottom of thepool where the chlorine is released slowly and a constant removal of themost contaminated water of low chlorine content from the surface of thepool.

During the regular operation of the pool a minimum of 50% of the poolslter rate is supplited from the gutter, However, by varying the positionof valve 26, as much as to 100% of liow can be obtained from the poolsurface giving in eifect a bottom supply, top takeoif recirculationsystem. p

Having described my invention I claim:

1. In a water distribution system for a swimming pool including a gutterhaving a front wall constituted by a pipe extending around the peripheryof the pool and an anode located in at least a portion of said pipe, aWeir section comprising:

means forming a notch in the upper portion of said pipe, said notchopening into said pipe,

a removable weir section mounted in said notch in sealing engagementtherewith while permitting water to flow through the lower portion ofsaid pipe, said `weir having a transverse passage therethrough,

a gate pivoted to said top portion of said weir section on an axisextending longitudinally of said pipe, said gate being pivot-ablebetween a vertical position in which it closes the passage created bysaid notch and a horizontal position in which it opens said passage,

and means for selectively locking said gate in either of its twopositions.

2. In a water distribution system for a swimming pool including a gutterhaving a front wall constituted by a pipe extending around theperpriphery of the pool, a Weir section comprising:

the top portion of said pipe having a notch formed by top edges, sideedges and bottom edges in said pipe,

a wall sealing each side of said notch while leaving the lower portionof said pipe unobstructed to the passage of water, said wall having abottom flange having an upper sunface flush with the bottom edge of saidnotch,

a removable -bottom plate in sealing engagement with said upper surfaceof said flange and said bottom edge,

a removable top plate disposed in said notch and having an upper surfacesubstantially llush `with the upper surface of said pipe,

a gate pivoted to said top plate on an axis extending longitudinally otsaid pipe, said gate being pivotable between a vertical position inwhich it closes the passage created by said notch and a horizontalposition in which it opens said passage,

and means for selectively locking said gate in either of its twopositions.

3. In a water distribution system for a swimming pool including a gutterhaving a front wall constituted by a pipe extending around the peripheryof the pool, a weir section comprising:

means forming a notch in the upper portion of said pipe, said notchopening into said pipe,

a removable weir section mounted in said notch in sealing engagementtherewith while leaving the lower portion of said pipe unobstructed tothe passage of water, said Weir having a transverse passagetherethrough,

a gate pivoted to the top portion of said Weir section on an axisextending longitudinally `of said pipe, said gate being pivotable'between a vertical position in which it closes the passage created bysaid notch and Ia horizontal position in which it opens said passage,

and means for selectively locking said gate in either of its twopositions.

4. In a water distribution system for a swimming pool including a gutterhaving a front wall constituted by a pipe extending around the peripheryof the pool, a `Weir section comprising:

means forming a notch in the upper portion of said pipe to form atransverse passage through said pipe, said notch opening into said pipe,

a removable bottom plate in sealing engagement with said pipe at thebottom of said notch while leaving the lower portion of said pipeunobstructed to the passage of water,

a removable top plate disposed in said notch and having an upper surfacesubstantially ilush with the upper surface of said pipe,

a gate pivoted to said top plate on a horizontal axis extendinglongitudinally of said pipe, said gate being pivotable down to avertical position in which it closes the passage created by said notchand up to a horizontal position in which it opens said passage,

a retainer arm pivoted on a vertical axis in said top plate, said arrnselectively providing a support for holding said gate in a horizontalposition and an abutment for blocking movement out of a verticalposition.

S. In a water distribution system for a swimming pool including a gutterhaving a front wall constituted by a pipe extending around the peripheryof the pool and an anode located in at least a portion of said pipe, aweir section comprising:

means forming a notch in the upper portion of said pipe, said notchopening into said pipe,

means in the wall of said pipe immediately below said notch forelectrically connecting said anode to said P1136,

said `anode being introducible into said pipe through said notch,

a removable Weir section mounted in said notch in sealing engagementtherewith while leaving the lower portion of said pipe unobstructed forthe passage of water, said weir having =a transverse passagetherethrough.

6. In a water distribution system for a swimming pool including a gutterhaving a front wall constituted by a pipe extending around the peripheryof the pool and an anode located in at least a portion of said pipe, aweir section comprising:

means forming a notch in the upper portion of said pipe, said notchopening into said pipe,

means in the wall of said pipe immediately below said notch forelectrically connecting said anode to said pipe,

said anode being introducible into said pipe through said notch,

a removable Weir section mounted in said notch in sealing engagementtherewith while leaving the lower portion unobstructed to the passage ofwater, said Weir having a transverse passage therethrough,

a gate pivoted to the top portion of said weir section on an axisextending longitudinally of said pipe, said gate being pivotable betweena vertical position in which it closes the passage created by said notchand a horizontal position in which it opens said passage,

and means for selectively locking said gate in either of its twopositions.

'7. A water distribution system for a swimming pool comprising:

a surge tank having lilters therein,

means forming an open gutter around the periphery of said pool andconnected to said surge tank,

a pipe extending around the periphery of said pool and forming the innerwall of said gutter,

a plurality of outlet nozzles in said pipe directing water downwardlyinto said pool,

at least one transverse passageway through the upper portion of saidpipe,

means for selectively opening or closing said passagea main drain andconduit connecting the bottom of said pool to said surge tank, aselectively positionable valve in said conduit,

and a pump and conduit means connected between said surge tank and pipeto draw water through said filters and into said pipe.

8. A water distribution system for a swimming pool comprising:

a surge tank having filters therein,

means forming an open gutter around the periphery of said pool andconnected to said surge tank,

a pipe extending around the periphery of said pool and forming the innerwall of said gutter,

a plurality of outlet nozzles in said pipe directing water downwardlyinto said pool,

at least one transverse passageway through the upper portion of saidpipe,

a main drain and conduit connecting the bottom of said pool to saidsurge tank, a selectively positionable valve in said conduit,

and a pump and conduit means connected between said Surge tank and pipeto draw water through said filters and into said pipe.

9. A water distribution system for a swimming pool comprising:

a surge tank having ilters therein,

means forming an open gutter around the periphery of said pool andconnected to said surge tank,

a pipe extending around the periphery of said pool and forming the innerwall of said gutter,

a plurality of outlet nozzles in said pipe directing water downwardlyinto said pool,

at least one transverse passageway through the upper portion of saidpipe,

means for selectively opening or closing said passage- Ways a main drainand conduit connecting the bottom of said pool to said surge tank, aselectively positionable valve in said conduit, said main drain andconduit being adapted to maintain the water level in said surge tank,above said lters when said pool is full, and without How of water fromsaid gutters,

and a pump and conduit `means connected between said surge tank and pipeto draw water through said lters and into said pipe.

10. A water distribution system for a swimming pool having angularcorners comprising,

a surge tank having filters therein,

means forming an open gutter around the periphery 10 of said pool andconnected to said surge tank,

a pipe extending around the periphery of said pool and forming the innerwall of said gutter,

a plurality of outlet nozzles in said pipe directing water downwardlyinto said pool,

a transverse passageway through the upper portion of said pipe locatedat each corner of said pool, said .passageways being similarly disposedwith respect to said corners,

means for selectively opening or closing said passage- Way,

a main drain and conduit connecting the bottom of 1 t? said pool to saidsurge tank, a selectively positionable valve in said conduit, and a pumpand cond-uit means connected between said surge tank and pipe to drawwater through said lters and into said pipe.

References Cited UNlTED STATES PATENTS 758,822 5/ 1904 Collis. 2,619,45511/1952 Harris et al 204-197 2,809,752 10/1957 Leslie 210--169 X2,846,385 8/1958 Buchan 2(34-197 X 2,932,397 4/1960 Ogden 4-172 X3,152,059 10/1964 Wellington 204-197 3,155,989 ll/l964 Anderson 210-169X 3,263,811 8/1966 Baker et al 210-169 X FOREIGN PATENTS 248,053 10/1962 Australia,

REUBEN FRIEDMAN, Primary Examiner. F. MEDLEY, Assistant Examiner.

